I wanted a TBolt just so i can make it BH209 capable AND i can size a 405Win bullet to shoot sabotless. They are actually .410 or .411 IIRC. 40cals should also knurl up if i went with a .408 CheyTac barrel . They also have a 1-14 to 1-16 twist.

Plus i would retain the abilty to shoot the conicals with other subs.